import { createStore,applyMiddleware,compose } from 'redux'  // 引入createStore方法
import thunk from 'redux-thunk' //引入redux-thunk中间件
import reducer from './reducer'    
// const store = createStore(reducer,window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__()) // 创建数据存储仓库
const composeEnhancers =   window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ ?
    window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__({}):compose

const enhancer = composeEnhancers(applyMiddleware(thunk))

const store = createStore( reducer, enhancer) // 创建数据存储仓库
export default store   //暴露出去